In a mobile IP network, when a mobile node changes its point of attachment to the network, a handover may occur between the current access router (CR) and a new access router (NR). The association of a mobile node with a CR may be handed over to a NR for a variety of reasons. For example, the mobile node may have physically moved to another location where the CR is no longer able to provide IP connectivity to the mobile node. Therefore, the mobile node re-associates with an NR for IP connectivity. Similarly, changes in network traffic demands may cause the CR associated with a mobile node to become overloaded. In this case, the association of the mobile node can be changed to a NR that is less loaded.
Mobile IP is described in more detail in IETF specifications. The basic idea of the mobile IP is that the mobile node can be always identified by its home address, regardless of its current point of attachment to the Internet. When the mobile Node is away from the home network it is also associated with a care-of address, which provides information about the mobile node's current location. Typically during handovers between the access routers the care-of address changes but the home address stays the same.
In any case, an IP level handover between points of attachment causes a mobile node to reconnect to the IP network through a NR instead of a CR. Such a handover may occur between access routers disposed within the same administrative (or routing) domain or across administrative domains. Prior to initiating an actual handover process, a mobile node needs to know the IP address of the NR and to verify that the NR supports features requires by the mobile node, such as quality of service (QoS), header compression, etc.
It is with respect to these considerations and others that the present invention has been made, and will be understood by reading and studying the following specification.